Prior to commissioning the system I needed to run through the inspection and testing for the solar sub panel.
Many of the tests did not apply as the relevant wires are simply not present – the array cables are 2 core live/neutral (no earth conductor), so R1/R2 testing cannot be carried out.
I could still perform insulation resistance tests as well as RCD tests on all the RCBOs, although this required ordering a new cable as my 3 wire IEC cable was showing no connectivity on the neutral wire!
The commissioning process was pretty straight forward and involved turning a known load appliance on and off several times as well as turning the solar RCBO off/on to ensure the CT clamps were functioning as expected.
I set the Site Maximum Import limit to 60A so as not to overload the DNO supply cartridge fuse.
I also set the Grid profile to “G99-1-9:2022 G100-2-2:2023 UK PEL 7.36kW Export” as directed by UK Power Networks following my G99 application.
The checklist complete I was able to start setting up my Home Assistant Energy dashboard.
It took me a while to sort all of the relevant sensors, some I had to create as the Enphase integration does not show battery charge or discharge, I had to derive this data from the Myenergi CT clamp data.
Later still I realised I had named them backwards (charge/discharge for the battery) and had to rename/update them so they showed up correctly.
I have already had a day of no peak energy usage, where I was able to run from off-peak electric (26.3kW) almost no peak (1.9kW) solar (23.04kW) and battery (18kW) for a total cost of £3.01 including the £0.42 standing charge for the day, considering that I still used 51.5kWh of electricity that day is pretty good going for mid April.
On good days I have flipped my peak/off-peak from 75%/25% to 20%/80% or better and on bad days 35%/65% with an average electricity consumption still around 60kWh a day this should lead to a return on investment in 3-5 years.
Summer should be better and things will improve even further once I add my East/West array and then add a fourth battery to bring my storage capacity up to 20kWh.
This is my energy usage profile for April so far
I am still working on the sensors in Home Assistant and am not convinced I have them all set correctly yet.
Batteries only show from 17th April as that is when I created those sensors, (pink is battery charge, light green battery consumption) but I am unsure why it is not showing Solar consumption after this date on the monthly energy usage chart.